Got the bigger panels to work. Unfortunately they are much stiffer than anticipated. Expected capton foil, got 0.5mm fiberglass (FR4). Well, we’ll need more force then.
Also the HDMI sink now works. I’m genuinely surprised how easy HDMI is. Made my own EDID, the FPGA registers as an ordinary HDMI screen and is driven by the laptop computer in mirrored display mode. The area the actual LED matrix maps to is configurable during runtime.
Funfact: The HDMI signal still contains the good old horizontal and vertical blanking intervals. A remembrance to the old CRTs and their slow slow electromagnets. Amazing how much bandwidth is wasted for that.
Next: sRGB-Gamma correction.